Silicone Bouncing Putty is back! Synthesized in 1943 at DOW Corning as a possible substitute for natural rubber, for over fifty years it has remained a popular "toy". Sold as "Silly Putty" and "Thinking Putty", it is one of the most interesting materials to study. It bounces like a super ball, it flows slowly like slime, shears when quickly pulled and lifts ink off printed matter. Threads of it are attracted to a static charge. Containing a heat-sensitive dye, this silicone bouncing putty changes color with the heat of your hand and from the heat generated from pulling and stretching. 91 g (1/5 lb).